Aircraft, aircraft wings and associated shear ties

ABSTRACT

Aircraft, aircraft wings and associated shear ties are disclosed. An example apparatus includes a first panel coupled to a second panel to define a wing box; a rib disposed chordwise within the wing box; and a stringer disposed spanwise within the wing box immediately adjacent at least one of the first panel or the second panel, the rib including a shear tie including first and second legs extending in opposite directions, the first and second legs to be coupled to at least one of the first panel, the second panel, or the stringer.

FIELD OF THE DISCLOSURE

This disclosure relates generally to aircraft and, more particularly, toaircraft, aircraft wings and associated shear ties.

BACKGROUND

Many aircraft include wings. In some examples, these wings include ribsfor structural stability and/or other reasons. To couple the ribs to thepanels of the wings, in some examples, shear ties are used.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of an example aircraft on which theexample shear ties disclosed herein can be implemented.

FIG. 2 illustrates a partial cutaway view of an example wing includingexample ribs having example shear ties in accordance with the teachingof this disclosure.

FIG. 3 illustrates an example rib that can be used to implement the ribsof FIG. 2.

FIGS. 4-6 illustrate different views of an example first shear tie thatcan be used to implement the example shear ties of FIGS. 2 and/or 3.

FIG. 7A illustrates an isometric view of example shear ties structuredaccording to FIGS. 4-6 that can be used to implement the example shearties of FIGS. 2 and/or 3.

FIGS. 7B and 7C illustrate opposing isometric views of an example ribthat can be used to implement the ribs of FIGS. 2 and/or 3.

FIGS. 8-10 illustrate different views of an example second shear tiethat can be used to implement the shear ties of FIGS. 2 and/or 3.

FIG. 11A illustrates an isometric view of example shear ties structuredaccording to FIGS. 8-10 that can be used to implement the example shearties of FIGS. 2 and/or 3.

FIGS. 11B and 11C illustrate opposing isometric views of an example ribthat can be used to implement the ribs of FIGS. 2 and/or 3.

FIGS. 12-14 illustrate different views of an example third shear tiethat can be used to implement the example shear ties of FIGS. 2 and/or3.

FIG. 15A illustrates an isometric view of example shear ties structuredaccording to FIGS. 12-14 that can be used to implement the example shearties of FIGS. 2 and/or 3.

FIGS. 15B and 15C illustrate opposing isometric views of an example ribthat can be used to implement the ribs of FIGS. 2 and/or 3.

FIG. 16 illustrates an isometric view of an example fourth shear tiethat can be used to implement the example shear ties of FIGS. 2 and/or3.

FIG. 17 illustrates an example rib including an example fifth shear tiecoupled to an example stringer and an example panel that can be used toimplement the example shear ties, ribs, stringers and panels of FIG. 2and/or the rib of FIG. 3.

FIG. 18 illustrates a detailed view of the coupling between the exampleshear tie, the example stringer and the example panel of FIG. 17.

FIG. 19 illustrates a detailed elevation view of the coupling betweenthe example shear tie, the example stringer and the example panel ofFIG. 17.

FIG. 20 illustrates an isometric view an example rib including anexample fifth shear tie that can be used to implement the example shearties of FIGS. 2 and/or 3.

The figures are not to scale. Wherever possible, the same referencenumbers will be used throughout the drawing(s) and accompanying writtendescription to refer to the same or like parts.

DETAILED DESCRIPTION

The examples disclosed herein relate to example aircraft havingintegrally stiffened wing panels and/or skins (e.g., composite wingstructures including metallic ribs) and/or composite wing panels and/orskins including fastened stringers. In some examples, aircraftimplemented according to the teachings of this disclosure includeexample wings and/or example ribs having shear ties that reduce and/oreliminate the number of shims used when assembling the aircraft wing.

In some examples, the number of shims may be reduced by structuring theexample shear ties to increase an allowable pull-up gap (e.g., afastener pull up) and/or a build tolerance prior to coupling the rib tothe adjacent components (e.g., the stringer, the panels) of the wingassembly while maintaining a threshold pull-up force(s). In someexamples, the threshold pull-up gap may be approximately 0.012 inchesand/or 0.016 inches and/or between about 0.008 inches and 0.016 inches.In some examples, the threshold pull-up force may be between about 250pounds (lbs.) and 350 lbs. However, the threshold pull-up gap may be adifferent amount (e.g., 0.0.015 inches, 0.17 inches, 0.020 inches, 0.1inches, etc.) depending on the design characteristics and/or designparameters. As used herein, the phrase “pull-up gap” refers to the gapbetween a shear tie and an opposing surface (e.g., a surface of astiffener, a surface of a panel of a wing, etc.) prior to fastenerinstallation and assembly. In other words, a greater allowable pull-upgap means that a shear tie is moved a greater distance to close and/ordecrease a gap during the assembly process between the shear tie and apanel to which the shear tie is to be fastened. Similarly, a lesserallowable pull-up gap means that a shear tie is moved a lesser distanceto close and/or decrease a gap during assembly between the shear tie anda panel to which the shear tie is to be fastened.

By reducing and/or eliminating the number of shims included between theribs and the panels of the aircraft wing, in some examples, the weightof the aircraft may be reduced, the cost of producing the aircraft maybe decreased and/or the throughput of manufacturing the aircraft may beincreased all while providing a robust shear tie. By reducing and/oreliminating the number of shims included when assembling an aircraftwing, in some examples, the number of shimming mills in the assemblyplant may be reduced, the footprint in the assembly plant associatedwith assembling the aircraft wing may be reduced, the production flowtime may be reduced and/or recurring and/or non-recurring productioncosts may be reduced. Further, in some examples, by reducing and/oreliminating the number of shims included when assembling an aircraftwing, worker ergonomics may be improved given the weight of the shimsand/or the confined space within the wing box where the shims wouldotherwise be placed.

In some examples, the shear ties disclosed herein are structured to havea moderate level of flexibility and/or compliance while not exceedingstatic and/or fatigue stresses allowable for the material of the sheartie and/or the associated rib. The shear ties and/or the rib may beformed of aluminum or any other suitable material. In some examples, thestatic stresses are between about 30-40 kilopounds per square inch (KSI)pounds and the fatigue stresses are between about 15-20 KSI.

The example shear ties disclosed herein may be formed as a one-sidedshear tie and/or a two-sided shear tie including tabs (e.g., tab outs).As used herein, a one-sided shear tie provides fastening access from oneside of the shear tie and a two-sided shear tie provides fasteningaccess from both sides of the shear tie. The tabs may be relativelyflexible and/or act as springs (e.g., a leaf spring) to increase theallowable pull-up gap between a shear tie and an associated wing panel.In other words, the flexibility of the tabs enables the tabs to be drawntoward an adjacent surface to close a relatively larger pull-up gap whena fastener(s) fastens the shear tie, the stringer and the associatedpanel. Additionally or alternatively, the example shear ties disclosedherein may be formed by scaling the example shear tie designs to achievea threshold pull-up capability (e.g., 0.012 inch pull-up capability, a0.016 inch pull-up capability). Regardless of the configuration of theexample shear ties implemented according to the teachings of thisdisclosure, the examples disclosed herein reduce and/or eliminate thenumber of shims used when assembling an aircraft wing.

FIG. 1 depicts an example aircraft 100 including an example fuselage 101and example engines 102 coupled to example wings 104. In this example,each of the wings 104 includes first and second panels 106, 108 that maybe formed of a composite material and/or a carbon fiber reinforcedplastic material.

FIG. 2 illustrates a partial cutaway view of one of the example wings104 that can be used to implement the wings 104 of the aircraft 100 ofFIG. 1. In the illustrated example, the wing 104 includes the first andsecond panels 106, 108 and ribs 202 that extend in a chordwise directionbetween the first and second panels 106, 108. As shown in theillustrated example, to increase the stability of the respective panels106, 108, example stringers 204 are coupled spanwise between the ribs202 along the length of the wing 104. In some examples, some of thestringers 204 are disposed adjacent the first panel 106 and others ofthe stringers 204 are disposed adjacent the second panel 108.

To couple the ribs 202, the stringers 204 and the panels 106 and/or 108together, in the illustrated example, the ribs 202 include example shearties 206 through which fasteners 208 extend. The shear ties 206 may beintegral to the ribs 202 or may be coupled to the ribs 202. In someexamples, two fasteners 208 extend through the shear ties 206 that areimplemented as one-sided shear ties where a one-sided shear tie providesfastening access from one side of the shear tie 206. In some examples,four fasteners 208 extend through the shear ties 206 that areimplemented as two-sided shear ties where a two-sided shear tie providesfastening access from both sides of the shear tie 206. However, in otherexamples, any number of fasteners 208 may be used to couple the shearties 206 to the first panel 106, the second panel 108 and/or thestringers 204.

Regardless of the configuration of the example shear ties 206 used tocouple the stringers 204, the ribs 202 and the panels 106 and/or 108together, the example shear ties 206 enable the pull-up gap between theshear ties 206, the stringer 204 and/or and the panel 106 and/or 108 tosatisfy a threshold prior to the fasteners 208 coupling the shear ties206, the stringers 204 and the panels 106 and/or 108 together. In someexamples, a pull-up gap may be present prior to installing a fastenerbased on manufacturing variability and/or other factors. In someexamples, the threshold pull-up gap that is closable using the examplesdisclosed herein may be greater than the pull-up gap that may beprovided by known examples (e.g., 0.005 inches-0.008 inches). In someexamples, the threshold pull-up gap is approximately 0.012 inches and/or0.016 inches and/or between about 0.008 inches and 0.016 inches.

In some examples, the wing 104 may be assembled by positioning thestringers 204 spanwise overtop of the second panel 108 and positioningthe ribs 202 chordwise overtop of the stringers 204 and adjacent thesecond panel 108. A pull-up gap may be defined between the shear tie 206of the rib 202 and at least one of the stringer 204 or the second panel108. In some examples, the wing 104 may be further assembled bypositioning the stringers 204 spanwise overtop of the ribs 202 andadjacent the first panel 106. The fasteners 208, when installed, maydecrease the pull-up gap between the shear ties 206, the stringer 204and the first panel and/or the second panel 108.

FIG. 3 illustrates an isometric view of an example rib 301 that can beused to implement the example ribs 202 of FIG. 2. In the illustratedexample, the rib 301 includes example bays 302, example stiffeners 304,and example shear ties 305 on a first side 308 of the rib 301 andexample shear ties 306 on a second side 312 of the rib 301. To enablethe stringers 204 to extend between the shear ties 305, 305, in thisexample, the rib 301 defines apertures 314 between adjacent ones of theshear ties 305, 306. Additionally, in the illustrated example, the rib301 includes an example web 316, example web pads 318 surroundingexample apertures 320, a first chord 322 adjacent the first side 308 ofthe rib 301 and a second chord 324 adjacent the second side 312 of therib 301. As shown in the example of FIG. 3, the bays 302 are defined bythe stiffeners 304 and the chords 322, 324.

FIGS. 4-6 illustrate different views of an example shear tie 401 thatcan be used to implement the shear ties 206 of FIG. 2 and/or the shearties 305, 306 of FIG. 3. In the illustrated example of FIG. 4, the sheartie 401 is a two-sided shear tie including a cleat and/or a base 402having a first tab and/or leg 404, a second tab and/or leg 406, a thirdtab and/or leg 408 and a forth tab and/or leg 410. In this example, thefirst and second legs 404, 406 are spaced from one another by an examplefirst arc-shaped aperture 411 and the third and fourth legs 408, 410 arespaced from one another by an example second arc-shaped aperture 412.While the apertures 411, 412 are arch-shaped in this example, theapertures 411, 412 may be any other shape.

In some examples, spacing the first and second legs 404, 406 from oneanother and spacing the third and fourth legs 408 410 from one anotherincreases the flexibility of the legs 404, 406, 408 and 410 and/orenables a length of legs 404, 406, 408 and 410 to be lesser as comparedto some examples disclosed herein. For example, the legs 404, 406, 408and 410 may be structured to be relatively flexible and/or to act asleaf springs to enable a threshold pull-up gap to be closed and/ordecreased when coupling the rib 202 and the first and/or second panels106, 108 and/or the stringers 204. In some examples, the thresholdpull-up gap is 0.012 inches and/or 0.016 inches and/or between about0.008 inches and 0.016 inches. However, the threshold pull-up gap may beany other distance depending on the design specifications, etc.

In some examples, to enable the shear tie 401 to be coupled to the firstand/or second panels 106, 108 and/or to the stringers 204, the legs 404,406, 408 and 410 define apertures 413 through which the fasteners 208extend. The apertures 413 may be positioned toward the edges and/or endsof the legs 404, 406, 408 and 410 to maximize the flexibility of thelegs 404, 406, 408 and 410. In this example, the apertures 413 aresymmetric about a longitudinal axis 414 and/or a transverse axis 416 ofthe shear tie 401. However, in other examples, the apertures 413 are notsymmetric about the longitudinal axis 414 and/or the transverse axis416. While the apertures 413 are depicted in particular locations on thelegs 404, 406, 408 and 410 and having a particular size and shape, theapertures 413 may be in any other location and may have any size and/orshape. While the legs 404, 406, 408 and 410 are shown including a singleaperture, more or fewer apertures may be defined by one or more of thelegs 404, 406, 408 and 410 (e.g., 0, 2, 3, etc.).

In the illustrated example, an example fillet and/or an angledintersection 418 extends along a central portion 419 of the cleat 402 tocouple the cleat 402 and an example web 420 of the shear tie 401. Inthis example, to enable forces and/or loads (e.g., shear loads) to betransferred through the shear tie 401 and/or to provide a load path forthe rib 202, the stringer 204, the first panel 106 and/or the secondpanel 108, the shear tie 401 includes an example flange 422 that boundsthe web 420. In some examples, the flange 422 is a V-shaped flangeand/or a stiffener that is angled relative to the cleat 402 to form aV-shaped web. In the example of FIG. 4, the flange 422 includes a firstportion 424 and a second portion 426 that are symmetric about acenterline and/or axis 428 of the web 420. However, in other examples,the first and second portions 424, 426 may not be symmetric. In thisexample, the first portion 424 is at between about a 20-degree angle anda 70-degree angle 429 (FIG. 6) relative to the centerline 428 of thesecond portion 401 and the second portion 426 is at between about anegative 20-degree angle and a negative 70-degree angle 430 (FIG. 6)relative to the centerline 428.

In the illustrated example, the first and second portions 424, 426 ofthe flange 422 are coupled to an example chord 432 that can be used toimplement the chord 322 and/or 324 of FIG. 3. As shown in the example ofFIG. 4, corners 427 of the web 420 adjacent the coupling between theflange 422 and the chord 432 may be rounded. To form the roundedcorners, in this example, the first and second portions 424, 426 of theflange 422 are splayed adjacent the coupling with the chord 432. In thisexample, stiffeners 434 extend from the chord 432 and define a bay 436in which a web 438 is disposed.

FIG. 5 illustrates another isometric view of the example shear tie 401of FIG. 4 showing an opposite side of the shear tie 401 as compared tothe view shown in FIG. 4. As shown in FIG. 5, first opposing edgesand/or sides 502, 504 are substantially parallel to one another andsecond opposing edges and/or sides 506, 508 of the cleat 402 aresubstantially parallel to one another. As used herein, substantiallyparallel means between about zero and five degrees of parallel and/oraccounts for manufacturing tolerances.

FIG. 6 illustrates an elevation view of the example shear tie 401 ofFIG. 4. As shown in the example of FIG. 6, the chord 432 and thestiffeners 434 define opposing fittings (e.g., bathtub fittings) 602,604 having rounded corners. In this example, chamfered and/or angledsurfaces and/or fillets 605 are provided at the intersection between theweb 420 and the flange 422. FIG. 7A illustrates two of the shear ties401 of FIG. 4 being formed of a single piece of material (e.g., amonolithic part) to enable the shear ties 401 to be coupled together. Inthe example of FIG. 7A, the adjacent shear ties 401 define an aperture702 through which the stringer 204 extends when the shear tie 401 isused to couple the rib 202, the stringer 204 and the first panel 106and/or the second panel 108 together.

FIGS. 7B and 7C illustrate opposing isometric views of an example rib704 that can be used to implement the example rib 202 of FIG. 2 and/orthe example rib 301 of FIG. 3. In the illustrated example of FIGS. 7Band 7C, the shear tie 401 is structured according to the example sheartie 401 of FIGS. 4-6 where the side shown in FIG. 7B includes the chord432 and the stiffeners 434 and the side shown in FIG. 7C does notinclude the chord 432 and the stiffeners 434. Thus, the side of the rib704 shown in FIG. 7C illustrates the web 438 without the inclusion ofthe chord 432 and the stiffeners 434. While the example rib 704 of FIGS.7B and 7C includes one shear tie structured according to the exampleshear tie of FIGS. 4-6, the rib 704 of FIGS. 7b and 7C may include anynumber of such shear ties. Referring to FIG. 7B, the example rib 704includes the chord 432 and the stiffeners 434 that extend substantiallyperpendicularly relative to one another. As used herein, substantiallyperpendicularly means between about zero degrees and five degrees ofperpendicular and/or accounts for manufacturing tolerances.

FIGS. 8-10 illustrate different views of another example shear tie 801that can be used to implement the shear ties 206 of FIG. 2 and/or theshear ties 305 and/or 306 of FIG. 3. In the illustrated example of FIG.8, the shear tie 801 is a two-sided shear tie including a cleat 802having a first tab and/or leg 804 and a second tab and/or leg 806. Incontrast to the example of FIGS. 4-6, the first leg 804 of FIG. 8 isformed as a single leg without an aperture separating the first leg 804into a first sub-leg (e.g., the first leg 404) and a second sub-leg(e.g., the second leg 406) and without separating the second leg 806into a third sub-leg (e.g., the third leg 408) and a fourth sub-leg(e.g., the fourth leg 410).

In contrast to the example of FIG. 4-6, to compensate for the width ofthe legs 804, 806 of FIG. 8 being greater than the width of the legs404, 406, 408 and 410 of FIG. 4 and to enable the first and second legs804, 806 of FIG. 8 to attain similar flexibly to the example legs 404,406, 408 and 410 of FIG. 4, a length 1002 (FIG. 10) of the first leg 804is greater than a length 606 (FIG. 6) of the first leg 404. In someexamples, the legs 804, 806 are structured to be relatively flexible toenable a threshold pull-up gap to be achieved, closed and/or decreasedwhen coupling the rib 202 and the first and/or second panels 106, 108and/or the stringers 204. In some examples, the threshold pull-up gap is0.012 inches and/or 0.016 inches and/or between about 0.008 inches and0.016 inches. However, the threshold pull-up gap may be any otherdistance depending on the design specifications, etc.

In some examples, to enable the shear tie 801 to be coupled to the firstand/or second panels 106, 108 and/or to the stringers 204, the legs 804,806 define apertures 808 through which the fasteners 208 extend. Whilethe apertures 808 are depicted in particular locations on the legs 804,806 and having a particular size and shape, the apertures 808 may be inany other location and may have any size and/or shape. While each of thelegs 804, 806 is shown as including two apertures, more or fewerapertures may be defined by one or more of the legs 804, 806 (e.g., 0,1, 3, etc.). In some examples, the apertures 808 are symmetric about alongitudinal axis 810 and/or a transverse axis 812 of the shear tie 801.However, in other examples, the apertures 808 are not be symmetric aboutthe longitudinal axis 810 and/or the transverse axis 812.

In this example, to enable forces and/or loads (e.g., shear loads) to betransferred through the shear tie 801, an example flange 814 extendsfrom the cleat 802 and bounds an example web 816 of the shear tie 801.Based on the first and second legs 804, 806 being longer relative to thelegs 404, 406, 408 and 410 of FIG. 4, in this example, a central portion817 of the cleat 802 that bounds the web 816 has a width 1004 (FIG. 10)that is lesser than a width of the central portion 419 of FIG. 4.

In the illustrated example, the flange 814 is angled relative to thecleat 802 to form a V-shaped web. In the example of FIG. 8, the flange814 includes a first portion 818 and a second portion 820 that aresymmetric about a centerline and/or axis 821 of the web 816. However, inother examples, the first and second portions 818, 820 may not besymmetric. In this example, the first portion 818 is at between about a20-degree angle and a 70-degree angle 824 (FIG. 10) relative to thecenterline 821 and the second portion 820 is at between about a negative20-degree angle and a negative 70-degree angle 826 (FIG. 10) relative tothe centerline 821.

In the illustrated example, the flange 814 is coupled to a chord 828that can be used to implement the chord 322 and/or 324 of FIG. 3. Inthis example, stiffeners 830 extend from the chord 828 and define a bay832 in which a web 834 is disposed. In some examples, the web 834 can beused to implement the web 316 of FIG. 3.

FIG. 9 illustrates another isometric view of the example shear tie 801of FIG. 8 showing an opposite side of the shear tie 801 as compared tothe view shown in FIG. 8 where the side of the shear tie 801 shown inFIG. 8 includes the chord 828 and the stiffeners 830 and the side of theshear tie 801 shown in FIG. 9 does not include the chord 828 and thestiffeners 830. Thus, the side of the shear tie 801 shown in FIG. 9illustrates the web 834 without the inclusion of the chord 828 and thestiffeners 830. In this example, chamfered and/or angled surfaces and/orfillets 902 are provided at the intersection between the web 816 and theflange 814. FIG. 10 illustrates an elevation view of the example sheartie 801 of FIG. 8 where the side of the shear tie 801 shown in FIG. 10is the same side of the shear tie 801 as shown in FIG. 9. In thisexample, the chord 828 and the stiffeners 830 are shown in the view ofFIG. 8 but not in the view of FIG. 10. FIG. 11A illustrates three of theshear ties 801 being formed of a single piece of material (e.g., amonolithic part) to enable the shear ties 801 to be coupled together. Inthe example of FIG. 11A, the adjacent shear ties 801 define apertures1102 through which the stringers 204 extend when the shear tie 801 isused to couple the rib 202, the stringers 204 and the first panel 106and/or the second panel 108 together.

FIGS. 11B and 11C illustrate opposing isometric views of an example rib1104 that can be used to implement the example rib 202 of FIG. 2 and/orthe rib 301 of FIG. 3. In the illustrated examples of FIGS. 11B and 11C,the shear tie 801 is structured according to the example shear tie 801of FIGS. 8-10. While the example rib 1104 of FIGS. 11B and 11C includesone shear tie structured according to the example shear tie of FIGS.8-10, the rib 1104 of FIGS. 11b and 11C may include any number of suchshear ties.

FIGS. 12-14 illustrate different views of another example shear tie 1201that can be used to implement the shear ties 206 of FIG. 2 and/or theshear ties 305, 306 of FIG. 3. In the illustrated example of FIG. 12,the shear tie 1201 is a one-sided shear tie including a cleat 1202 fromwhich a first flange 1203, a second flange 1204 and a V-shaped stiffenerand/or flange 1206 extend. In some examples, the first and secondflanges 1203, 1204 are structured and/or configured to receive and/ortransfer first forces and/or loads (e.g., heal/toe effect loads) and theV-shaped stiffener 1206 is structured and/or configured to receiveand/or transfer second forces and/or loads (e.g., shear loads).

In the illustrated example, a first aperture 1208 is defined by thecleat 1202 and associated with a first fitting (e.g., a first bathtubfitting) 1210 and a second aperture 1212 is defined by the cleat 1202and associated with a second fitting (e.g., a second bathtub fitting)1214. In this example, the first fitting 1210 is defined by the cleat1202, the first flange 1203 and a first portion 1216 of the V-shapedstiffener 1206 and the second fitting 1214 is defined by the cleat 1202,the second flange 1204 and a second portion 1218 of the V-shapedstiffener 1206. As shown in the illustrated example, the cleat 1202, thefirst flange 1203, the V-shaped stiffener 1206 and the second flange1204 bound different portions of a web 1219 of the shear tie 1201.

In some examples, the apertures 1208, 1212 are offset and/ornon-symmetric relative to a longitudinal axis 1220 of the shear tie 206.In some examples, the apertures 1208, 1212 are symmetric relative to atransverse axis 1222 of the shear tie 1201. However, in other examples,the apertures 1208, 1212 are symmetrically positioned relative to thelongitudinal axis 1220 and/or non-symmetrically positioned relative tothe transverse axis 1222. Further, while the apertures 1208, 1212 aredepicted in particular locations on the fittings 1210, 1214, theapertures 1208, 1212 may be in any other locations. While the fittings1210, 1214 are shown having one aperture, more or fewer apertures may bedefined by the cleat 1202.

In some examples, the cleat 1202, the first flange 1203, the secondflange 1204 and the V-shaped stiffener 1206 are structured to berelatively flexible to enable a threshold pull-up gap to be closedand/or decreased when coupling the rib 202 to the first and/or secondpanels 106, 108 and/or to the stringers 204. In some examples, thethreshold pull-up gap is 0.012 inches and/or 0.016 inches and/or betweenabout 0.008 inches and 0.016 inches. However, the threshold pull-up gapmay be any other distance depending on the design specifications, etc.In the illustrated example, the first flange 1203, the V-shapedstiffener 1206 and/or the second flange 1204 are coupled to an examplechord 1224 that can be used to implement the chord 322 and/or 324 ofFIG. 3. In this example, stiffeners 1226 extend from the chord 1224 anddefine a bay 1228 in which a web 1230 is disposed.

FIG. 13 illustrates another isometric view of the example shear tie 1201of FIG. 12 showing an opposite side of the shear tie 1201 as compared tothe view shown in FIG. 12. As shown in the example of FIG. 13, the firstflange 1203 is L-shaped including a tapered surface 1302 relative to abase 1304 of the cleat 1202. However, the flanges 1203, 1204 may haveany other cross-section. In this example, the chord 1224 and thestiffeners 1226 are shown in FIG. 12 but not in FIG. 13. FIG. 14illustrates an elevation view of the example shear tie 1201 of FIG. 12.As shown in the example of FIG. 14, the shear tie 1201 is symmetricabout a center line and/or axis 1402. However, in other examples, theshear tie 1201 is not symmetric relative to the center line 1402.Further, as shown in the example of FIG. 14, chamfered and/or taperedsurfaces and/or fillets 1404, 1406, 1408 are provided at theintersection between the web 1219 and the flanges 1203, 1204, 1206.

FIG. 15A illustrates three of the shear ties 1201 of FIG. 12 beingformed of a single piece of material (e.g., a monolithic part) to enablethe shear ties 1201 to be coupled together. In this example, theadjacent shear ties 1201 define apertures 1502 through which thestringers 204 extend when the shear tie 1201 is used to couple the rib202, the stringers 204 and the first panel 106 and/or the second panel108 together.

FIGS. 15B and 15C illustrate opposing isometric views of an example rib1504 that can be used to implement the example rib 202 of FIG. 2 and/orthe rib 301 of FIG. 3. In the illustrated examples of FIGS. 15B and 15C,the shear tie 1201 is structured according to the example shear ties1201 of FIGS. 12-14. While the example rib 202 of FIGS. 15B and 15Cinclude one shear tie structured according to the example shear tie ofFIGS. 12-14, the rib 202 of FIGS. 15b and 15C may include any number ofsuch shear ties.

FIG. 16 illustrates example shear ties 1601 that can be used toimplement the shear ties 206 of FIG. 2 and/or the shear ties 305, 306 ofFIG. 3. The shear ties 1601 of FIG. 16 are substantially similar to theshear ties 401 of FIG. 7A. However, in contrast to the shear ties 401 ofFIG. 7A, the shear ties 1601 of FIG. 16 include a stiffener, protrusion,gusset and/or rib 1602 centrally disposed on the web 420. In someexamples, the stiffener 1602 is provided on both sides of the shear tie1601 where the stiffeners 1602 may be similar and/or different from oneanother depending on the design specifications. In other examples, thestiffener 1602 is provided on one of the sides of the shear tie 1601 andnot on the other of the sides of the shear tie 1601. While one stiffener1602 is illustrated on the shear tie 1601 of FIG. 16, in other examples,the shear tie 1601 may include additional stiffeners (e.g., 2, 3, etc.).In some such examples, one side of the shear tie 1601 may include afirst number (e.g., 1, 2, 3, etc.) of the stiffeners and another side ofthe shear tie 1601 may include a second number of stiffeners (e.g., 1,2, 3, etc.) where the first number is different than the second number.

FIGS. 17-19 illustrates different views of an example rib 1702, anexample shear tie 1704, example stringers and/or T-shaped stringers 1706and an example panel 1708 that can be used to implement the rib 202, theshear ties 206, the stringers 204 and the second panel 108 of FIG. 2and/or the rib 301 of FIG. 3. In this example, the shear tie 1704 isstructured and/or configured to enable the pull-up gap between the shearties 206 and the panel 106 and/or 108 to satisfy a threshold prior tothe fastener 208 coupling the shear tie 1704, the stringer 1706 and thepanel 1708.

In the illustrated example, the rib 1702 includes a web 1710 disposed inbays 1712 defined by stiffeners 1714, a chord 1716 and the shear tie1704. In this example, to enable the stringers 1706 to pass through therib 1702, the shear ties 1704 and/or the rib 1702 include arc-shapedflanges 1718 that define apertures 1720 through which the stringers 1706extend. In the example of FIG. 17, the stiffeners 1714 intersect therespective arch-shaped flanges 1718 centrally.

FIG. 18 illustrates a detailed view of the rib 1702, the shear tie 1704,the stringer 1706 and the panel 1708 and FIG. 19 illustrates a detailedelevation view of the rib 1702, the shear tie 1704, the stringer 1706and the panel 1708. Referring to FIG. 19, arrows 1902 are included toshow a pull-up gap 1904 between the stringer 1706 and the shear tie1704. In some examples, the pull-up gap is approximately 0.012 inchesand/or 0.016 inches and/or between about 0.008 inches and 0.016 inchesprior the fastener 208 coupling the shear tie 1704, the stringer 1706and the panel 1708.

FIG. 20 illustrates a portion of an example rib 2002 that can be used toimplement the rib 202 of FIG. 2. The rib 2002 of FIG. 20 is similar tothe rib 1702 of FIG. 17. However, in contrast to the rib 1702 of FIG.17, the rib 2002 of FIG. 20 includes an example shear tie 2004 having acleat 2005 including a central protrusion 2006 through which an aperture2008 extends. In some examples, the central protrusion 2006 isstructured and/or configured to be positioned between the stringers 204when the shear tie 2004 is used to couple the rib 2002, the stringer 204and the first and/or second panels 106 and/or 108 together. In suchexamples, the fastener 208 that extends through the aperture 2008 maynot pass through a corresponding aperture of the stringer 1706.

From the foregoing, it will be appreciated that example methods,apparatus and articles of manufacture have been disclosed that relate toexample shear ties configured and/or structured to have spring-likeproperties within the constraints of the static and/or fatigueproperties of the material from which the shear ties are made. In someexamples, the shear ties are made of aluminum. However, any othermaterial(s) may be used to produce the shear ties. In some examples, theexample shear ties enable the pull-up capabilities to be increasedbetween about 80% and 120% relative to some examples. Such an approachof changing the pull-up capabilities (e.g., increasing the pull-upcapabilities), enables fewer shims to be used when assembling and/ormanufacturing aircraft and/or associated aircraft wings. In someexamples, the example shear ties are one-sided shear ties. In someexamples, the example shear ties are two-sided shear ties.

In some examples, the ribs may be formed as a one-sided monolithicaluminum machined part including an integral web stiffener, a sculptedflange and a baseline plate sized between about 3-5 inches wide. In someexamples, the shear ties are between about 4 inches and 5 inches tall, 7inches wide and between about 2 inches and 4 inches deep. To enable afastener(s) that couples the shear tie, the stringer and the wing paneland/or skin to be closer to the web of the shear tie, in some examples,stress peaks may be directed toward the edge of the flange of the sheartie rather than a fillet of the shear tie. To reduce cantilever bending,in some examples, the fastener(s) extending through the shear tie may bespaced from a gusset(s) of the shear tie. In some example, to deterstringer flange edge margins from being affected when the fastener(s) isspaced from the gusset(s) of the shear ties, the gusset(s) may be cutback, removed and/or reduced. In examples in which the example shearties are one-sided, the shear ties may be coupled to the stringer andthe panel and/or skin of the wing using a single row of fasteners. Inexamples in which the shear ties are two-sided, the shear ties may becoupled to the stringer and the panel and/or the skin of the wing usinga double row of fasteners. However, other fastener arrangements may beused for either of the one-sided shear tie or the two-sided shear tie(e.g., a single row of fasteners, off-set placement of fasteners,triangular placement of fasteners, a triple row of fasteners, etc.).

An example apparatus includes a first panel coupled to a second panel todefine a wing box; a rib disposed chordwise within the wing box; and astringer disposed spanwise within the wing box immediately adjacent atleast one of the first panel or the second panel, the rib including ashear tie including first and second legs extending in oppositedirections, the first and second legs to be coupled to at least one ofthe first panel, the second panel, or the stringer.

In some examples, the first and second legs enable a pull-up gap to bedecreased from a threshold value when a fastener couples the shear tie,the stringer and at least one of the first panel or the second panel. Insome examples, the apparatus includes a plurality of stringers and aplurality of ribs, each of the ribs including a plurality of shear ties.In some examples, the shear tie includes a stiffener structured toreceive a shear load when the shear tie couples, via a fastener, therib, the stringer and at least one of the first panel or the secondpanel. In some examples, the shear tie further includes a web bounded bythe stiffener to form a V-shaped web. In some examples, the shear tiefurther includes a chord and a cleat, the stiffener positioned betweenthe chord and the cleat. In some examples, the first and second legsextend in opposite directions from the stiffener, the first and secondlegs structured to enable the pull-up gap to satisfy a threshold valuewhen a fastener couples the shear tie, the stringer and at least one ofthe first panel or the second panel.

In some examples, the first leg includes a first sub-leg and a secondsub-leg and the second leg include a third sub-leg and a fourth sub-leg,the first sub-leg spaced from the second sub-leg to increase aflexibility of the first sub-leg and the second sub-leg, the thirdsub-leg spaced from the fourth sub-leg to increase a flexibility of thethird sub-leg and the fourth sub-leg. In some examples, the fastener isa first fastener, the first leg defines a first aperture to receive thefirst fastener to couple the rib, the stringer and at least one of thefirst panel or the second panel, the second leg defines a secondaperture to receive a second fastener to couple the rib, the stringerand at least one of the first panel or the second panel. In someexamples, the first leg includes first apertures, the second legincludes second apertures, the first and second apertures beingsymmetric about at least one of a longitudinal axis of the shear tie ora transverse axis of the shear tie.

An example apparatus includes a first panel coupled to a second panel todefine a wing box; a rib disposed chordwise within the wing box; and astringer disposed spanwise within the wing box immediately adjacent atleast one of the first panel or the second panel, the rib includingmeans for enabling a pull-up gap to satisfy a threshold value greaterthan 0.008 inches prior to a fastener coupling the rib, the stringer andat least one of the first panel or the second panel, the pull-up gapbeing defined between the rib and at least one of the stringer, thefirst panel, or the second panel. In some examples, the means forenabling the pull-up gap to satisfy the threshold value includesflexible legs of a shear tie. In some examples, the means for enablingthe pull-up gap to satisfy the threshold value includes a shear tieincluding a stiffener structured to receive a shear load when thefastener extends through the shear tie to couple the rib, the stringerand at least one of the first panel or the second panel. In someexamples, the shear tie further includes a web bounded by the stiffenerto form a V-shaped web. In some examples, the shear tie further includesa chord and a cleat, the stiffener positioned between the chord and thecleat. In some examples, the cleat includes a first leg and a secondleg, the first and second legs extending in opposite directions from thestiffener, the first and second legs structured to enable the pull-upgap to satisfy the threshold value. In some examples, the fastenerincludes a plurality of fasteners and the shear tie further includes afirst flange and a second flange, the first flange, the cleat, and thestiffener defining a first fitting, the second flange, the cleat, andthe stiffener defining a second fitting, a first aperture being definedby the cleat at the first fitting and a second aperture being defined bythe cleat at the second fitting, the first and second apertures toreceive the respective fasteners to couple the rib, the stringer and atleast one of the first panel or the second panel. In some examples, thecleat includes a first leg and a second leg extending in a firstdirection, the first leg spaced from the second leg to increase aflexibility of the first leg and the second leg. In some examples, theapparatus includes a gusset coupled between the web and the cleat.

An example method includes positioning a rib chordwise adjacent a firstpanel of a wing; positioning a stringer spanwise overtop of the rib andbetween the first panel and the rib, a pull-up gap being defined betweena shear tie of the rib and at least one of the stringer or the firstpanel, the pull-up gap being greater than 0.008 inches; and coupling theshear tie, the stringer, and the first panel using a fastener todecrease the pull-up gap.

An apparatus including a rib including a shear tie including first andsecond legs extending in opposite directions, the rib to be disposedwithin a wingbox of an aircraft wing defined by first and second panels,the first and second legs of the shear tie to be coupled to at least oneof the first panel or the second panel.

In some examples, the shear tie includes a stiffener structured toreceive a shear load when the shear tie couples, via a fastener, therib, a stringer and at least one of the first panel or the second panel.In some examples, the shear tie further includes a web bounded by thestiffener to form a V-shaped web. In some examples, the shear tiefurther includes a chord and a cleat, the stiffener positioned betweenthe chord and the cleat. In some examples, the first leg includes afirst sub-leg and a second sub-leg and the second leg include a thirdsub-leg and a fourth sub-leg, the first sub-leg spaced from the secondsub-leg to increase a flexibility of the first sub-leg and the secondsub-leg, the third sub-leg spaced from the fourth sub-leg to increase aflexibility of the third sub-leg and the fourth sub-leg.

Although certain example methods, apparatus and articles of manufacturehave been disclosed herein, the scope of coverage of this patent is notlimited thereto. On the contrary, this patent covers all methods,apparatus and articles of manufacture fairly falling within the scope ofthe claims of this patent.

What is claimed is:
 1. An apparatus comprising: a first panel coupled toa second panel to define a wing box; a stringer disposed spanwise withinthe wing box immediately adjacent at least one of the first panel or thesecond panel; and a rib disposed chordwise within the wing box, the ribincluding a shear tie, the shear tie including a web, a cleat coupled tothe web, and first and second legs extending in opposite directions froma central portion of the cleat, the first and second legs cantileveredoutward from the central portion of the cleat in a chordwise directionsuch that distal ends of the first and second legs are spaced apart fromthe web, the first and second legs coupled to at least one of thestringer or one of the first panel or the second panel.
 2. The apparatusof claim 1, wherein the first and second legs reduce a pull-up gap froma threshold value when a fastener couples the shear tie, the stringerand one of the first panel or the second panel.
 3. The apparatus ofclaim 1, further including a plurality of stringers and a plurality ofribs including a plurality of shear ties.
 4. The apparatus of claim 1,wherein the shear tie includes a stiffener structured to receive a shearload when the shear tie couples, via a fastener, the rib, the stringerand one of the first panel or the second panel.
 5. The apparatus ofclaim 4, wherein the web is bounded by the stiffener to form a V-shapedweb.
 6. The apparatus of claim 4, wherein the shear tie further includesa chord, the stiffener positioned between the chord and the cleat. 7.The apparatus of claim 6, wherein the first and second legs extend inopposite directions from the stiffener, the first and second legsstructured to enable the pull-up gap to satisfy a threshold value whenthe fastener couples the shear tie, the stringer and one of the firstpanel or the second panel.
 8. The apparatus of claim 1, wherein thefirst leg includes a first sub-leg and a second sub-leg and the secondleg includes a third sub-leg and a fourth sub-leg, the first sub-legspaced from the second sub-leg, the third sub-leg spaced from the fourthsub-leg.
 9. The apparatus of claim 1, wherein the first leg defines afirst aperture to receive a first fastener to couple the rib, thestringer and one of the first panel or the second panel, and wherein thesecond leg defines a second aperture to receive a second fastener tocouple the rib, the stringer and one of the first panel or the secondpanel.
 10. The apparatus of claim 1, wherein the first leg includesfirst apertures, the second leg includes second apertures, the first andsecond apertures are symmetric about at least one of a longitudinal axisof the shear tie or a transverse axis of the shear tie.
 11. An apparatuscomprising: a first panel coupled to a second panel to define a wingbox; a rib disposed chordwise within the wing box; and a stringerdisposed spanwise within the wing box immediately adjacent at least oneof the first panel or the second panel, the rib including a shear tiehaving a web, a cleat coupled to the web, and first and second legsextending in opposite directions from a central portion of the cleat,the first and second legs cantilevered outward from the central portionof the cleat in a chordwise direction such that distal ends of the firstand second legs are spaced apart from the web, the first and second legsenabling a pull-up gap to satisfy a threshold value greater than 0.008inches prior to a fastener coupling the rib, the stringer and one of thefirst panel or the second panel, the pull-up gap defined between the riband at least one of the stringer or one of the first panel or the secondpanel.
 12. The apparatus of claim 11, wherein the shear tie includes astiffener structured to receive a shear load when the fastener extendsthrough the shear tie to couple the rib, the stringer and one of thefirst panel or the second panel.
 13. The apparatus of claim 12, whereinthe web is further includes a web bounded by the stiffener to form aV-shaped web.
 14. The apparatus of claim 13, wherein the shear tiefurther includes a chord and a cleat, the stiffener positioned betweenthe chord and the cleat.
 15. The apparatus of claim 11, wherein thefirst leg includes a first sub-leg and a second sub-leg, the firstsub-leg spaced from the second sub-leg.
 16. The apparatus of claim 11,further including a gusset coupled between the web and the cleat.
 17. Amethod comprising: positioning a rib chordwise adjacent a first panel ofa wing; positioning a stringer spanwise overtop the rib and between thefirst panel and the rib, a pull-up gap defined between a shear tie ofthe rib and at least one of the stringer or the first panel of greaterthan 0.008 inches, the shear tie including a web, a cleat coupled to theweb, and first and second legs extending in opposite directions from acentral portion of the cleat, the first and second legs cantileveredoutward from the central portion of the cleat in a chordwise directionsuch that distal ends of the first and second legs are spaced apart fromthe web; and coupling the shear tie, the stringer, and the first panelusing a fastener to decrease the pull-up gap.
 18. An apparatuscomprising: a rib including a shear tie, the shear tie including firstand second legs extending in opposite directions, the first legincluding a first sub-leg and a second sub-leg spaced from the firstsub-leg by a first aperture, the second leg including a third sub-legand a fourth sub-leg spaced from the third-leg by a second aperture, therib disposed within a wing box of an aircraft wing defined by first andsecond panels, the first and second legs of the shear tie to couple toone of the first panel or the second panel.
 19. The apparatus of claim18, wherein the shear tie includes a stiffener structured to receive ashear load when the shear tie couples, via a fastener, the rib, astringer and one of the first panel or the second panel.
 20. Theapparatus of claim 19, wherein the shear tie further includes a webbounded by the stiffener to form a V-shaped web.
 21. The apparatus ofclaim 19, wherein the shear tie further includes a chord and a cleat,the stiffener positioned between the chord and the cleat.